Field of the Invention
The present invention relates to a technique for transferring data.
Description of the Background Art
In an image processing apparatus such as an image pickup apparatus, generally, image data acquired by an image pickup device such as a CCD is once stored in a storing portion (for example, a DRAM or the like) in the image pickup apparatus. Then, the image data is read from the storing portion and are subjected to various image procesings.
For example, Japanese Patent Application Laid-Open No. 2011-113234 describes an image processing apparatus for reading image data from an image data storing portion storing the image data and correcting a distortion of an image in a distortion correcting portion.
Referring to the image processing apparatus described in the Japanese Patent Application Laid-Open No. 2011-113234 , image data is read by using a DMAC (Direct Memory Access Controller) in response to a transfer request for image data from a distortion correcting portion. In this case, a processing speed of a distortion correction is influenced by a reading speed of an image data storing portion. In other words, a transfer speed of image data from the image data storing portion to the distortion correcting portion is low. For this reason, the processing speed of the distortion correction is reduced.
The reduction in the processing speed might be caused also in a transfer of image data in response to a transfer request given from a processing portion for performing another image processing.